diff --git a/registrasion/controllers/invoice.py b/registrasion/controllers/invoice.py
index de401d31a11a539873c4ee99f0befe192eef3a99..fce09f8faca9f5370b0484ae73e0775e9de88d21 100644
--- a/registrasion/controllers/invoice.py
+++ b/registrasion/controllers/invoice.py
@@ -142,7 +142,6 @@ class InvoiceController(object):
 
         return False
 
-
     def _refresh(self):
         ''' Refreshes the underlying invoice and cart objects. '''
         self.invoice.refresh_from_db()
diff --git a/registrasion/tests/controller_helpers.py b/registrasion/tests/controller_helpers.py
index 476351ddfea5cc59e30d2c29823c3f4ef8b94c4f..ad8661b6d1627229a13ba75bce24dfce4e3a6c8c 100644
--- a/registrasion/tests/controller_helpers.py
+++ b/registrasion/tests/controller_helpers.py
@@ -3,7 +3,6 @@ from registrasion.controllers.invoice import InvoiceController
 from registrasion import models as rego
 
 from django.core.exceptions import ObjectDoesNotExist
-from django.core.exceptions import ValidationError
 
 
 class TestingCartController(CartController):
@@ -41,7 +40,7 @@ class TestingInvoiceController(InvoiceController):
         self.validate_allowed_to_pay()
 
         ''' Adds a payment '''
-        payment = rego.ManualPayment.objects.create(
+        rego.ManualPayment.objects.create(
             invoice=self.invoice,
             reference=reference,
             amount=amount,
diff --git a/registrasion/tests/test_discount.py b/registrasion/tests/test_discount.py
index e91053789fccf8e20b5a493e3a8f965a65a34307..e84ca283b238be41c3a2f0cc073ce94cd2b6d792 100644
--- a/registrasion/tests/test_discount.py
+++ b/registrasion/tests/test_discount.py
@@ -5,7 +5,6 @@ from decimal import Decimal
 from registrasion import models as rego
 from registrasion.controllers import discount
 from controller_helpers import TestingCartController
-from controller_helpers import TestingInvoiceController
 
 from test_cart import RegistrationCartTestCase
 
diff --git a/registrasion/tests/test_invoice.py b/registrasion/tests/test_invoice.py
index b121bfa1d034707a82156e6158203909b1665a91..7854680dc4c4b6455c38e29b4b050f4c9e919bb4 100644
--- a/registrasion/tests/test_invoice.py
+++ b/registrasion/tests/test_invoice.py
@@ -197,7 +197,7 @@ class InvoiceTestCase(RegistrationCartTestCase):
     def test_cannot_generate_blank_invoice(self):
         current_cart = TestingCartController.for_user(self.USER_1)
         with self.assertRaises(ValidationError):
-            invoice_1 = TestingInvoiceController.for_cart(current_cart.cart)
+            TestingInvoiceController.for_cart(current_cart.cart)
 
     def test_cannot_pay_implicitly_void_invoice(self):
         cart = TestingCartController.for_user(self.USER_1)
@@ -210,8 +210,6 @@ class InvoiceTestCase(RegistrationCartTestCase):
         with self.assertRaises(ValidationError):
             invoice.validate_allowed_to_pay()
 
-
-
     # TODO: test partially paid invoice cannot be void until payments
     # are refunded
 
diff --git a/registrasion/util.py b/registrasion/util.py
index fb97d1d5cba90778e8bfec02d77a3dd2c5eb92ac..3df548004868728690cb5459ec68bd0a9ca3de16 100644
--- a/registrasion/util.py
+++ b/registrasion/util.py
@@ -2,6 +2,7 @@ import string
 
 from django.utils.crypto import get_random_string
 
+
 def generate_access_code():
     ''' Generates an access code for users' payments as well as their
     fulfilment code for check-in.
diff --git a/registrasion/views.py b/registrasion/views.py
index 1b0fe64655b38b3c65ef8eaecfa5e0215af34d54..f07956476b0ee14b50e96851da35fa870c28ba87 100644
--- a/registrasion/views.py
+++ b/registrasion/views.py
@@ -484,7 +484,7 @@ def invoice(request, invoice_id, access_code=None):
     if not current_invoice.can_view(
             user=request.user,
             access_code=access_code,
-        ):
+            ):
         raise Http404()
 
     data = {